For primary diagnosis and treatment of cardiovascular diseases, such as atherosclerosis, ischemia, hypertension and other, interventional cardiology in a cardiac catheterization laboratory are suitable. Cardiac catheterization stands for the insertion of small tubes (catheters) through arteries and/or veins to the myocardium. In order to visualize coronary arteries and cardiac chambers with real-time X-ray imaging, an opaque contrast agent is injected through the catheter. This procedure leads to an image referred to as an angiogram, which is standard for diagnosing cardiovascular disease.
X-ray based cardiac catheterization systems represent the current standard of care and provide imaging modalities for both diagnostic and therapeutic procedures in cardiology. In particular, they are applied for generating real-time images of obstructions to blood flow in the coronary arteries. Real-time X-ray imaging is utilized to guide insertion of balloon-tipped catheters to the point of obstruction, if such is identified, and allows for treatment by angioplasty and stent placement.
Current cardiac catheterization systems enable the majority of minimally invasive procedures in a catheterization laboratory and all have the same fundamental architecture that uses a point X-ray source and a large-area detector. On a monitor, a shadowgram image of the patient is obtained, which is obtained from the detector.
However, during interventions under X-ray guidance, several movements originating from different anatomical structures may be observed in 2D images. The estimation of one particular motion may be affected by others. For example, cardiac motion estimation is impacted by breathing motion and movements of the bones due to the patient's movements. Several techniques, such as transparent motion estimation, decompose 2D X-ray images into regions governed by independent movements.
US 2012/238871 A1 discloses an angiography system with a system control unit that generates a mask image that detects a reference image, effects a registration of the reference image to a C-arm, whereby if necessary a segmentation of the examination object is implemented in the reference image. Image regions lying inside of the segmentation are contrasted in order to generate a mask image, and the mask image from fluoroscopy live images acquired by the angiography system without contrast agent are subtracted in order to form a roadmap image.